Epidemiology and outcome ofScedosporium prolificansinfection, a review of 162 cases

Invasive Scedosporium sternal osteomyelitis following lung transplant: Cured

Scedosporium is an important pathogen in cystic fibrosis (CF) and post-transplant but rarely causes invasive infection. Treatment remains challenging, particularly due to inherent resistance to multiple antifungal agents. We present a young man with CF who developed invasive sternal and rib infection 10-months following lung transplant. The infection has been clinically and radiologically cured with extensive surgery and triazole therapy. This case highlights the importance of adjunctive surgery in addition to prolonged triazole treatment to manage invasive Scedosporium infections in immunosuppressed patients.

Emerging infections due to filamentous fungi in humans and animals: only the tip of the iceberg?

Over the last few decades, the number of patients susceptible to invasive filamentous fungal infections has steadily increased, especially in populations suffering from hematological diseases. The pathogens responsible for such mycoses are now quite well characterized, such as Aspergillus spp. - the most commonly isolated mold -, Mucorales, Fusarium spp., Scedosporium spp. or melanized fungi. An increase in the incidence of this category of 'emerging' fungi has been recently highlighted, evoking a shift in fungal ecology. Starting from these medical findings, taking a step back and adopt a wider perspective offers possible explanations of this phenomenon on an even larger scale than previously reported. In this review, we illustrate the link between emerging fungi in medicine and changes in ecology or human behaviours, and we encourage integrative approaches to apprehend the adverse effects of progress and develop preventive measures in vast domains, such as agriculture or medicine.

SUSCEPTIBILITY TEST FOR FUNGI: CLINICAL AND LABORATORIAL CORRELATIONS IN MEDICAL MYCOLOGY

During recent decades, antifungal susceptibility testing has become standardized and nowadays has the same role of the antibacterial susceptibility testing in microbiology laboratories. American and European standards have been developed, as well as equivalent commercial systems which are more appropriate for clinical laboratories. The detection of resistant strains by means of these systems has allowed the study and understanding of the molecular basis and the mechanisms of resistance of fungal species to antifungal agents. In addition, many studies on the correlation of in vitro results with the outcome of patients have been performed, reaching the conclusion that infections caused by resistant strains have worse outcome than those caused by susceptible fungal isolates. These studies have allowed the development of interpretative breakpoints for Candida spp. and Aspergillus spp., the most frequent agents of fungal infections in the world. In summary, antifungal susceptibility tests have become essential tools to guide the treatment of fungal diseases, to know the local and global disease epidemiology, and to identify resistance to antifungals.

Targeted Disruption of Melanin Biosynthesis Genes in the Human Pathogenic Fungus Lomentospora prolificans and Its Consequences for Pathogen Survival

The dematiaceous (melanised) fungus Lomentospora (Scedosporium) prolificans is a life-threatening opportunistic pathogen of immunocompromised humans, resistant to anti-fungal drugs. Melanin has been shown to protect human pathogenic fungi against antifungal drugs, oxidative killing and environmental stresses. To determine the protective role of melanin in L. prolificans to oxidative killing (H₂O₂), UV radiation and the polyene anti-fungal drug amphotericin B, targeted gene disruption was used to generate mutants of the pathogen lacking the dihydroxynaphthalene (DHN)-melanin biosynthetic enzymes polyketide synthase (PKS1), tetrahydroxynapthalene reductase (4HNR) and scytalone dehydratase (SCD1). Infectious propagules (spores) of the wild-type strain 3.1 were black/brown, whereas spores of the PKS-deficient mutant ΔLppks1::hph were white. Complementation of the albino mutant ΔLppks1::hph restored the black-brown spore pigmentation, while the 4HNR-deficient mutant ΔLp4hnr::hph and SCD-deficient mutant ΔLpscd1::hph both produced orange-yellow spores. The mutants ΔLppks1::hph and ΔLp4hnr::hph showed significant reductions in spore survival following H₂O₂ treatment, while spores of ΔLpscd1::hph and the ΔLppks1::hph complemented strain ΔLppks1::hph:PKS showed spore survivals similar to strain 3.1. Spores of the mutants ΔLp4hnr::hph and ΔLpscd1::hph and complemented strain ΔLppks1::hph:PKS showed spore survivals similar to 3.1 following exposure to UV radiation, but survival of ΔLppks1::hph spores was significantly reduced compared to the wild-type strain. Strain 3.1 and mutants ΔLp4hnr::hph and ΔLppks1::hph:PKS were resistant to amphotericin B while, paradoxically, the PKS1- and SCD1-deficient mutants showed significant increases in growth in the presence of the antifungal drug. Taken together, these results show that while melanin plays a protective role in the survival of the pathogen to oxidative killing and UV radiation, melanin does not contribute to its resistance to amphotericin B.

Lomentospora prolificans endocarditis--case report and literature review

BACKGROUND

Lomentospora prolificans (formally Scedosporium prolificans) is an environmental mould with a global distribution. Endocarditis caused by L. prolificans is a rare but serious emerging disease in immunocompromised patients. Prior to this case there have only been eight cases reported in the literature. Diagnosis can be challenging and there are no evidence-based guidelines for treatment.

CASE PRESENTATION

We report a 75-year-old woman with ovarian carcinoma who presented with fever after chemotherapy. Repeated sterile site cultures remained negative until day 22 of admission, when Lomentospora prolificans was isolated from blood cultures. Following extensive investigations, including Fluoro-D-glucose positron emission tomography (FDG-PET) and transoephageal echocardiography (TOE), the patient was diagnosed with endocarditis complicated by cerebral emboli. The patient was considered unsuitable for surgical intervention and passed away five days after the fungus was isolated.

CONCLUSION

Endocarditis caused by Lomentospora prolificans is a rare but emerging condition, with limited treatment options and a high mortality. Awareness of the increasing incidence of Lomentospora prolificans infection, diagnosed often at an advanced stage, with potential for endocarditis may prompt earlier echocardiography or FDG-PET imaging. Further studies are needed to determine the optimal combination and duration of anti-fungal agents, used in conjunction with aggressive surgical excision where feasible.

Emerging infections caused by non-Aspergillus filamentous fungi

There are three broad groups of non-Aspergillus moulds: the mucormycetes, the hyalohyphomycetes and the phaeohyphomycetes. Infections with these pathogens are increasingly reported, particularly in the context of increasing use of immunosuppressant agents and improved diagnostics. The epidemiology of non-Aspergillus mould infections varies with geography, climate and level of immunosuppression. Skin and soft-tissue infections are the predominant presentation in the immunocompetent host and pulmonary and other invasive infections in the immunocompromised host. The more common non-Aspergillus moulds include Rhizopus, Mucor, Fusarium and Scedosporium species; however, other emerging pathogens are Rasamsonia and Verruconis species, which are discussed in this article. Outbreaks of non-Aspergillus mould infections have been increasingly reported, with contaminated medical supplies and natural disasters as common sources. Currently culture and other conventional diagnostic methods are the cornerstone of diagnosis. Molecular methods to directly detect and identify mould pathogens in tissue and body fluids are increasingly used.

Scedosporium prolificans Endocarditis: Case Report and Literature Review

Scedosporium prolificans, a hyaline filamentous fungus, is widely distributed in the environment and is currently an emerging human pathogen, especially among immunocompromised patients. However, S. prolificans endocarditis is rare. We herein report a case of S. prolificans endocarditis in a 64-year-old patient with breast cancer in complete remission for 30 years after chemotherapy and radiation treatment who was not cured. Susceptibility testing showed resistance to all antifungal drugs, except echinocandin. A review of the literature revealed 10 cases of S. prolificans endocarditis; of these, only one involved an immunocompetent host with no risk factors and only two patients survived. In order to improve the mortality rate, it is necessary to establish rapid diagnostic methods and efficient therapeutic approaches.

Phaeohyphomycosis in Transplant Patients

Phaeohyphomycosis is caused by a large, heterogenous group of darkly pigmented fungi. The presence of melanin in their cell walls is characteristic, and is likely an important virulence factor. These infections are being increasingly seen in a variety of clinical syndromes in both immunocompromised and normal individuals. Transplant patients are especially at risk due their prolonged immunosuppression. There are no specific diagnostic tests for these fungi, though the Fontana-Masson stain is relatively specific in tissue. They are generally seen in a worldwide distribution, though a few species are only found in specific geographic regions. Management of these infections is not standardized due to lack of clinical trials, though recommendations are available based on clinical experience from case reports and series and animal models. Superficial infections may be treated without systemic therapy. Central nervous system infections are unique in that they often affect otherwise normal individuals, and are difficult to treat. Disseminated infections carry a high mortality despite aggressive therapy, usually with multiple antifungal drugs. Considerable work is needed to determine optimal diagnostic and treatment strategies for these infections.

Pulmonary scedosporiosis mimicking aspergilloma in an immunocompetent host: a case report and review of the literature

A case of localized lung scedosporiosis is reported here that mimicked aspergilloma in an immunocompetent host. Through this case the importance of considering Scedosporium spp. in differential diagnosis of locally invasive lung infections and fungal ball is highlighted. As it is difficult to differentiate Scedosporium from Aspergillus on clinical grounds, microscopy, radiology and histopathology, this case is further emphasizing the significance of the definitive etiological characterization of Scedosporium through culture or molecular diagnostic tools. Accurate identification of Scedosporium, surgical resection and high-dose voriconazole has been associated with favorable outcome in most reported cases of scedosporiosis.

Consensus guidelines for the treatment of invasive mould infections in haematological malignancy and haemopoietic stem cell transplantation, 2014

Mould species represent the pathogens most commonly associated with invasive fungal disease in patients with haematological malignancies and patients of haemopoietic stem cell transplants. Invasive mould infections in these patient populations, particularly in the setting of neutropenia, are associated with high morbidity and mortality, and significantly increase the complexity of management. While Aspergillus species remain the most prevalent cause of invasive mould infections, Scedosporium and Fusarium species and the Mucormycetes continue to place a significant burden on the immunocompromised host. Evidence also suggests that infections caused by rare and emerging pathogens are increasing within the setting of broad-spectrum antifungal prophylaxis and improved survival times placing immunosuppressed patients at risk for longer. These guidelines present evidence-based recommendations for the antifungal management of common, rare and emerging mould infections in both adult and paediatric populations. Where relevant, the role of surgery, adjunctive therapy and immunotherapy is also discussed.

DNA barcoding of fungi causing infections in humans and animals

Correct species identification is becoming increasingly important in clinical diagnostics. Till now, many mycological laboratories rely on conventional phenotypic identification. But this is slow and strongly operator-dependent. Therefore, to improve the quality of pathogen identification, rapid, reliable, and objective identification methods are essential. One of the most encouraging approaches is molecular barcoding using the internal transcribed spacer (ITS) of the rDNA, which is rapid, easily achievable, accurate, and applicable directly from clinical specimens. It relies on the comparison of a single ITS sequence with a curated reference database. The International Society for Human and Animal Mycology (ISHAM) working group for DNA barcoding has recently established such a database, focusing on the majority of human and animal pathogenic fungi (ISHAM-ITS, freely accessible at http://www.isham.org/ or directly from http://its.mycologylab.org). For some fungi the use of secondary barcodes may be necessary.

ESCMID and ECMM joint guidelines on diagnosis and management of hyalohyphomycosis: Fusarium spp., Scedosporium spp. and others

Mycoses summarized in the hyalohyphomycosis group are heterogeneous, defined by the presence of hyaline (non-dematiaceous) hyphae. The number of organisms implicated in hyalohyphomycosis is increasing and the most clinically important species belong to the genera Fusarium, Scedosporium, Acremonium, Scopulariopsis, Purpureocillium and Paecilomyces. Severely immunocompromised patients are particularly vulnerable to infection, and clinical manifestations range from colonization to chronic localized lesions to acute invasive and/or disseminated diseases. Diagnosis usually requires isolation and identification of the infecting pathogen. A poor prognosis is associated with fusariosis and early therapy of localized disease is important to prevent progression to a more aggressive or disseminated infection. Therapy should include voriconazole and surgical debridement where possible or posaconazole as salvage treatment. Voriconazole represents the first-line treatment of infections due to members of the genus Scedosporium. For Acremonium spp., Scopulariopsis spp., Purpureocillium spp. and Paecilomyces spp. the optimal antifungal treatment has not been established. Management usually consists of surgery and antifungal treatment, depending on the clinical presentation.

Invasive fungal infections in transplant recipients

Invasive fungal infections are an important cause of morbidity and mortality in hematopoietic stem cell transplant and solid organ transplant recipients. Evolving transplant modalities and techniques, complex and extensive immunosuppressant strategies, and the increased use of broad spectrum antifungal prophylaxis has greatly impacted the epidemiology and temporal pattern of invasive fungal infections in the transplant population. The goal of this article is to provide an up-to-date review of the most commonly encountered invasive fungal infections seen in transplant recipients, including epidemiology, risk factors, clinical features, diagnostic dilemmas, management and their overall influence on outcomes.

[Invasive fungal disease due to Scedosporium, Fusarium and mucorales]

The number of emerging organisms causing invasive fungal infections has increased in the last decades. These etiological agents include Scedosporium, Fusarium and mucorales. All of them can cause disseminated, virulent, and difficult-to treat infections in immunosuppressed patients, the most affected, due to their resistance to most available antifungal agents. Current trends in transplantation including the use of new immunosuppressive treatments, the common prescription of antifungal agents for prophylaxis, and new ecological niches could explain the emergence of these fungal pathogens. These pathogens can also affect immunocompetent individuals, especially after natural disasters (earthquakes, floods, tsunamis), combat wounds or near drowning. All the invasive infections caused by Scedosporium, Fusarium, and mucorales are potentially lethal and a favourable outcome is associated with rapid diagnosis by direct microscopic examination of the involved tissue, wide debridement of infected material, early use of antifungal agents including combination therapy, and an improvement in host defenses, especially neutropenia.

Identifying the emerging human pathogen Scedosporium prolificans by using a species-specific monoclonal antibody that binds to the melanin biosynthetic enzyme tetrahydroxynaphthalene reductase

The dematiaceous (melanized) fungus Scedosporium prolificans is an emerging and frequently fatal pathogen of immunocompromised humans and which, along with the closely related fungi Pseudallescheria boydii, Scedosporium apiospermum and S. aurantiacum in the Pseudallescheria-Scedosporium complex, is a contributing aetiology to tsunami lung and central nervous system infections in near-drowning victims who have aspirated water laden with spores. At present, the natural habitat of the fungus is largely unknown, and accurate detection methods are needed to identify environmental reservoirs of infectious propagules. In this study, we report the development of a monoclonal antibody (mAb) (CA4) specific to S. prolificans, which does not cross-react with closely related fungi in the Pseudallescheria-Scedosporium complex or with a wide range of mould and yeast species pathogenic to humans. Using genome sequencing of a soil isolate and targeted gene disruption of the CA4 antigen-encoding gene, we show that mAb CA4 binds to the melanin-biosynthetic enzyme tetrahydroxynaphthalene reductase. Enzyme-deficient mutants produce orange-brown or green-brown spore suspensions compared with the black spore suspension of the wild-type strain. Using mAb CA4 and a mAb (HG12) specific to the related fungi P. boydii, P. apiosperma, S. apiospermum and S. aurantiacum, we demonstrate how the mAbs can be used in combination with a semiselective isolation procedure to track these opportunistic pathogens in environmental samples containing mixed populations of human pathogenic fungi. Specificity of mAb CA4 was confirmed by sequencing of the internally transcribed spacer 1 (ITS1)-5.8S-ITS2 rRNA-encoding regions of fungi isolated from estuarine muds.

Scedosporium prolificans osteomyelitis following penetrating injury: A case report

Scedosporium prolificans are opportunistic moulds that can cause mycetoma following penetrating injuries. This fungus is more virulent than other species and treatment options are limited. Here we describe the first known case in the UK of S. prolificans osteomyelitis, in a 4 year old following penetrating injury. Successful outcome with limb salvage and foot function is achieved after repeated surgical debridement, and combination chemotherapy with voriconazole/terbinafine.

Invasive mold infections in solid organ transplant recipients

Invasive mold infections represent an increasing source of morbidity and mortality in solid organ transplant recipients. Whereas there is a large literature regarding invasive molds infections in hematopoietic stem cell transplants, data in solid organ transplants are scarcer. In this comprehensive review, we focused on invasive mold infection in the specific population of solid organ transplant. We highlighted epidemiology and specific risk factors for these infections and we assessed the main clinical and imaging findings by fungi and by type of solid organ transplant. Finally, we attempted to summarize the diagnostic strategy for detection of these fungi and tried to give an overview of the current prophylaxis treatments and outcomes of these infections in solid organ transplant recipients.

Scedosporium prolificans fungaemia in a patient with acute lymphoblastic leukaemia

Aggressive chemotherapy and immunosuppressive treatment may prolong patients' life, but influence the risk of severe, life-threatening infections. Here, we report the case of a 21-year-old caucasian female who developed a disseminated infection of Scedosporium prolificans after allogenic stem cell transplantation performed for treatment of relapsed acute lymphoblastic leukaemia. The pathogen was isolated from the blood and identified on the basis of its macroscopic and microscopic morphological features. The empirical treatment with amphotericin B provided no improvement. However, introduction of intravenous voriconazole resulted in amelioration of fever. Unfortunately, the patient died due to progression of underlying disease and multiorgan failure. However, this case report indicates a possible relevance of voriconazole-based treatment regimens in invasive S. prolificans infections.

Treatment of invasive fungal infections in cancer patients-updated recommendations of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO)

The Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO) here presents its updated recommendations for the treatment of documented fungal infections. Invasive fungal infections are a main cause of morbidity and mortality in cancer patients undergoing intensive chemotherapy regimens. In recent years, new antifungal agents have been licensed, and agents already approved have been studied in new indications. The choice of the most appropriate antifungal treatment depends on the fungal species suspected or identified, the patient's risk factors (e.g., length and depth of neutropenia), and the expected side effects. This guideline reviews the clinical studies that served as a basis for the following recommendations. All recommendations including the levels of evidence are summarized in tables to give the reader rapid access to the information.

Immunodetection of fungal and oomycete pathogens: established and emerging threats to human health, animal welfare and global food security

Filamentous fungi (moulds), yeast-like fungi, and oomycetes cause life-threatening infections of humans and animals and are a major constraint to global food security, constituting a significant economic burden to both agriculture and medicine. As well as causing localized or systemic infections, certain species are potent producers of allergens and toxins that exacerbate respiratory diseases or cause cancer and organ damage. We review the pathogenic and toxigenic organisms that are etiologic agents of both animal and plant diseases or that have recently emerged as serious pathogens of immunocompromised individuals. The use of hybridoma and phage display technologies and their success in generating monoclonal antibodies for the detection and control of fungal and oomycete pathogens are explored. Monoclonal antibodies hold enormous potential for the development of rapid and specific tests for the diagnosis of human mycoses, however, unlike plant pathology, their use in medical mycology remains to be fully exploited.

Population-based survey of filamentous fungi and antifungal resistance in Spain (FILPOP Study)

A population-based survey was conducted to investigate the epidemiology of and antifungal resistance in Spanish clinical strains of filamentous fungi isolated from deep tissue samples, blood cultures, and respiratory samples. The study was conducted in two different periods (October 2010 and May 2011) to analyze seasonal variations. A total of 325 strains were isolated in 29 different hospitals. The average prevalence was 0.016/1,000 inhabitants [corrected]. Strains were identified by sequencing of DNA targets and susceptibility testing by the European Committee for Antimicrobial Susceptibility Testing reference procedure. The most frequently isolated genus was Aspergillus, accounting for 86.3% of the isolates, followed by Scedosporium at 4.7%; the order Mucorales at 2.5%; Penicillium at 2.2%, and Fusarium at 1.2%. The most frequent species was Aspergillus fumigatus (48.5%), followed by A. flavus (8.4%), A. terreus (8.1%), A. tubingensis (6.8%), and A. niger (6.5%). Cryptic/sibling Aspergillus species accounted for 12% of the cases. Resistance to amphotericin B was found in 10.8% of the isolates tested, while extended-spectrum triazole resistance ranged from 10 to 12.7%, depending on the azole tested. Antifungal resistance was more common among emerging species such as those of Scedosporium and Mucorales and also among cryptic species of Aspergillus, with 40% of these isolates showing resistance to all of the antifungal compounds tested. Cryptic Aspergillus species seem to be underestimated, and their correct classification could be clinically relevant. The performance of antifungal susceptibility testing of the strains implicated in deep infections and multicentric studies is recommended to evaluate the incidence of these cryptic species in other geographic areas.

Externa otitis caused by the Graphium stage of Pseudallescheria apiosperma

We report a case of otomycosis caused by the Graphium stage of Pseudallescheria apiosperma in an immunocompetent 32 years old man who was suffering from hypoacusia and purulent otorrhea. Isolates were identified as Graphium stage of Pseudallescheria sp. on the basis of macroscopic and microscopic characteristics. Pseudallescheria apiosperma was correctly identified by PCR sequencing of ITS regions and β-tubulin gene. In this case the contamination could be due to intensive activity of gardening with poor hygiene.

Impact of multidrug-resistant organisms on patients considered for lung transplantation

Infections with multidrug-resistant organisms are a growing problem in lung transplant recipients. Carriage of drug-resistant bacteria and fungi before transplantation is an important risk factor for such infections. In that regard Pseudomonas aeruginosa and species of Burkholderia, Acinetobacter, non-tuberculous mycobacteria and Scedosporium are particularly important. An understanding of the impact of these organisms is essential to the evaluation of lung transplant candidates. The microbiology, epidemiology, clinical manifestations, and approach to these pathogens before transplant are reviewed in this article.

Scedosporium prolificans pericarditis and mycotic aortic aneurysm in a lung transplant recipient receiving voriconazole prophylaxis

Despite the adoption of antifungal prophylaxis, fungal infections remain a significant concern in lung transplant recipients. Indeed, some concern exists that such prophylaxis may increase the risk of infection with drug-resistant fungal organisms. Here, we describe a case of disseminated Scedosporium prolificans infection, presenting as pericarditis, which developed in a lung transplant patient receiving prophylactic voriconazole for 8 months. The epidemiology and clinical presentation of S. prolificans infections are reviewed, and controversies surrounding antifungal prophylaxis and the development of resistant infections are discussed.

Neuro-ophthalmology of invasive fungal sinusitis: 14 consecutive patients and a review of the literature

BACKGROUND

Invasive fungal sinusitis is a rare condition that usually occurs in immunocompromised patients and often presents as an orbital apex syndrome. It is frequently misdiagnosed on presentation and is almost always lethal without early treatment.

DESIGN

Retrospective case series of 14 consecutive patients with biopsy-proven invasive fungal sinusitis from four tertiary hospitals.

PARTICIPANTS

Fourteen patients (10 men and 4 women; age range 46-82 years).

METHODS

Retrospective chart review of all patients presenting with invasive fungal sinusitis between 1994 and 2010 at each hospital, with a close analysis of the tempo of the disease to identify any potential window of opportunity for treatment.

MAIN OUTCOME MEASURES

Demographic data, background medical history (including predisposing factors), symptoms, signs, radiological findings, histopathological findings, treatment approach and subsequent clinical course were recorded and analysed.

RESULTS

Only one patient was correctly diagnosed at presentation. Only two patients were not diabetic or immunocompromised. The tempo was acute in two patients, subacute in nine patients and chronic in three patients. In the subacute and chronic cases, there was about 1 week of opportunity for treatment, from the time there was a complete orbital apex syndrome, and still a chance for saving the patient, to the time there was central nervous system invasion, which was invariably fatal. Only two patients survived - both had orbital exenteration, as well as antifungal drug treatment.

CONCLUSIONS

Invasive fungal sinusitis can, rarely, occur in healthy individuals and should be suspected as a possible cause of a progressive orbital apex syndrome.

Pulmonary fungal infections

This review details some of the advances that have been made in the recent decade in the diagnosis, treatment and epidemiology of pulmonary fungal infections. These advances have occurred because of increasing knowledge regarding the fungal genome, better understanding of the structures of the fungal cell wall and cell membrane and the use of molecular epidemiological techniques. The clinical implications of these advances are more rapid diagnosis and more effective and less toxic antifungal agents. For example, the diagnosis of invasive pulmonary aspergillosis, as well as histoplasmosis and blastomycosis, has improved with the use of easily performed antigen detection systems in serum and bronchoalveolar lavage fluid. Treatment of angioinvasive moulds has improved with the introduction of the new azoles, voriconazole and posaconazole that have broad antifungal activity. Amphotericin B is less frequently used, and when used is often given as lipid formulation to decrease toxicity. The newest agents, the echinocandins, are especially safe as they interfere with the metabolism of the fungal cell wall, a structure not shared with humans cells. Epidemiological advances include the description of the emergence of Cryptococcus gattii in North America and the increase in pulmonary mucormycosis and pneumonia due to Fusarium and Scedosporium species in transplant recipients and patients with haematological malignancies. The emergence of azole resistance among Aspergillus species is especially worrisome and is likely related to increased azole use for treatment of patients, but also to agricultural use of azoles as fungicides in certain countries.

Fungal infection in solid organ recipients

In solid organ recipients, as with other immunosuppressed patients, infections by Candida spp. and Aspergillus spp. are the most frequent invasive mycoses. Infections by Cryptococcus spp. and fungi of the Mucorales order are less common. Infections by Fusarium spp. and Scedosporium spp. are very uncommon, except in patients undergoing hematopoietic stem cell transplant and patients with prolonged neutropenia. The risk factors for fungal infection are immunosuppression, surgery, viral co-infection, and environmental exposure. Diagnosis is challenging: blood culture is of little use, except in candidiasis and cryptococcosis, and the poor accuracy of antigen-based techniques, except in cryptococcosis, favors widespread use of empirical therapy. A delay in the initiation of therapy increases the already high mortality of these infections. The agents used to treat fungal infection are azoles, echinocandins, and lipid amphotericin. Administration depends on antifungal activity, drug-drug interactions with calcineurin inhibitors, and safety profiles (effects on grafts and other side effects).

Infection and colonisation due to Scedosporium in Northern Spain. An in vitro antifungal susceptibility and molecular epidemiology study of 60 isolates

Since the latest taxonomical changes in the genus Scedosporium by Gilgado et al. in 2010, no species-specific studies on epidemiology and antifungal susceptibility patterns (AFSP) have so far been published. This study aimed to provide qualitative epidemiological data of Scedosporium spp. isolated from cystic fibrosis (CF) patients and immunocompromised patients from Northern Spain. Isolates were identified by using amplified fragment length polymorphism (AFLP), and species-specific AFSP were generated for all currently available antifungal compounds. AFLP was a useful tool for identification to species-level and for the discrimination of inter- and intra-patient isolates. Scedosporium prolificans represents the most prevalent species in the respiratory tract of CF patients and immunocompromised patients in Northern-Spain, followed by Pseudallescheria boydii, P. apiosperma, and P. ellipsoidea. CF patients were exclusively colonised with either P. boydii or S. prolificans. Patients were colonised over years exclusively with isolates affiliated to one species, but some patients were colonised with multiple strains with different AFSP. The sum of those co-colonising strains in one patient, may appear in vitro and in vivo as a multi-resistant S. prolificans isolate, as strains are morphologically identical and might therefore be regarded as only one strain. A majority of Scedosporium strains (with exception of S. prolificans) were found susceptible for voriconazole and micafungin.

Species-specific antifungal susceptibility patterns of Scedosporium and Pseudallescheria species

Since the separation of Pseudallescheria boydii and P. apiosperma in 2010, limited data on species-specific susceptibility patterns of these and other species of Pseudallescheria and its anamorph Scedosporium have been reported. This study presents the antifungal susceptibility patterns of members affiliated with both entities. Clinical and environmental isolates (n = 332) from a wide range of sources and origins were identified down to species level and tested according to CLSI M38-A2 against eight antifungal compounds. Whereas P. apiosperma (geometric mean MIC/minimal effective concentration [MEC] values of 0.9, 2.4, 7.4, 16.2, 0.2, 0.8, 1.5, and 6.8 μg/ml for voriconazole, posaconazole, isavuconazole, itraconazole, micafungin, anidulafungin, caspofungin, and amphotericin B, respectively) and P. boydii (geometric mean MIC/MEC values of 0.7, 1.3, 5.7, 13.8, 0.5, 1.4, 2.3, and 11.8 μg/ml for voriconazole, posaconazole, isavuconazole, itraconazole, micafungin, anidulafungin, caspofungin, and amphotericin B, respectively) had similar susceptibility patterns, those for S. aurantiacum, S. prolificans, and S. dehoogii were different from each other. Voriconazole was the only drug with significant activity against S. aurantiacum isolates. The MIC distributions of all drugs except voriconazole did not show a normal distribution and often showed two subpopulations, making a species-based prediction of antifungal susceptibility difficult. Therefore, antifungal susceptibility testing of all clinical isolates remains essential for targeted antifungal therapy. Voriconazole was the only compound with low MIC values (MIC(90) of ≤ 2 μg/ml) for P. apiosperma and P. boydii. Micafungin and posaconazole showed moderate activity against the majority of Scedosporium strains.

Uncommon mold infections in hematological patients: epidemiology, diagnosis and treatment

Invasive fungal diseases continue to be an important cause of morbidity and mortality in immunosuppressed patients. This is of particular interest, since the progress we made in the treatment of underlying malignancies has led to an increase of the number of persons 'at high risk'. During the last few years, several changes in clinical practice in hematology (new immunosuppressants, hematopoietic stem cell transplants) have influenced the epidemiology of invasive fungal diseases; in particular, cases due to some uncommon etiologic agents are being increasingly reported, making it even more urgent to reconsider differential diagnoses in high-risk patients. A better understanding of epidemiology, risk factors and prognosis appears to be crucial to analyze prevention and diagnostic strategies, as well as to guarantee an early and adequate treatment.